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0032473509
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For reviews, see a
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For reviews, see (a) Corey, E. J.; Guzman-Perez, A. Angew. Chem., Int. Ed. 1998, 37, 388-401.
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Corey, E.J.1
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(b) Christoffers, J.; Mann, A. Angew. Chem., Int. Ed. 2001, 40, 4591-4597.
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Christoffers, J.1
Mann, A.2
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3
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0042929265
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For reviews on memory of chirality, see a
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For reviews on memory of chirality, see (a) Kawabata, T.; Fuji, K. Top. Stereochem. 2003, 23, 175-205.
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Top. Stereochem
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Kawabata, T.1
Fuji, K.2
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5
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37049069871
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For reactions related to memory of chirality, see a
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For reactions related to memory of chirality, see (a) Beagley, B.; Betts, M. J.; Pritchard, R. G.; Schofield, A.; Stoodley, R. J.; Vohra, S. J. Chem. Soc., Chem. Comm. 1991, 924-925.
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Beagley, B.1
Betts, M.J.2
Pritchard, R.G.3
Schofield, A.4
Stoodley, R.J.5
Vohra, S.6
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6
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0345022255
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(b) Kawabata, T.; Yahiro, K.; Fuji, K. J. Am. Chem. Soc. 1991, 113, 9694-9696.
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J. Am. Chem. Soc
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Kawabata, T.1
Yahiro, K.2
Fuji, K.3
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7
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0000297636
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(c) Betts, M. J.; Pritchard, R. G.; Schofield, A.; Stoodley, R. J.; Vohra, S. J. Chem. Soc., Perkin Trans. 1 1999, 1067-1072.
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J. Chem. Soc., Perkin Trans. 1
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Betts, M.J.1
Pritchard, R.G.2
Schofield, A.3
Stoodley, R.J.4
Vohra, S.5
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8
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0035906484
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(d) Gerona-Navarro, G.; Bonache, M. A.; Herranz, R.; García- López, M. T.; González-Muñiz, R. J. Org. Chem. 2001, 66, 3538-3547.
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J. Org. Chem
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Gerona-Navarro, G.1
Bonache, M.A.2
Herranz, R.3
García- López, M.T.4
González-Muñiz, R.5
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9
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0037561625
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(e) Bonache, M. A.; Gerona-Navarro, G.; Martín-Martínez, M.; García-López, M. T.; López, P.; Cativiela, C.; González-Muñiz, R. Synlett 2003, 1007-1011.
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Synlett
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Bonache, M.A.1
Gerona-Navarro, G.2
Martín-Martínez, M.3
García-López, M.T.4
López, P.5
Cativiela, C.6
González-Muñiz, R.7
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10
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0141757477
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(f) Carlier, P. R.; Zhao, H.; DeGuzman, J.; Lam, Polo, C.-H. J. Am. Chem. Soc. 2003, 125, 11482-11483.
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J. Am. Chem. Soc
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Carlier, P.R.1
Zhao, H.2
DeGuzman, J.3
Lam, P.C.-H.4
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11
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0037243455
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(g) Kawabata, T.; Ozturk, O.; Suzuki, H.; Fuji, K. Synthesis 2003, 505-508.
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(2003)
Synthesis
, pp. 505-508
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Kawabata, T.1
Ozturk, O.2
Suzuki, H.3
Fuji, K.4
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12
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0037222246
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(h) Kawabata, T.; Ozturk, O.; Chen, J.; Fuji, K. Chem. Commun. 2003, 162-163.
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Chem. Commun
, pp. 162-163
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Kawabata, T.1
Ozturk, O.2
Chen, J.3
Fuji, K.4
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13
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33845284917
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(i) Kawabata, T.; Matsuda, S.; Kawakami, S.; Monguchi, D.; Moriyama, K. J. Am. Chem. Soc. 2006, 128, 15394-15395.
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J. Am. Chem. Soc
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Kawabata, T.1
Matsuda, S.2
Kawakami, S.3
Monguchi, D.4
Moriyama, K.5
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14
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0034674351
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(a) Kawabata, T.; Suzuki, H.; Nagae, Y.; Fuji, K. Angew. Chem., Int. Ed. 2000, 39, 2155-2157.
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Angew. Chem., Int. Ed
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, pp. 2155-2157
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Kawabata, T.1
Suzuki, H.2
Nagae, Y.3
Fuji, K.4
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15
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0034736318
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(b) Kawabata, T.; Chen, J.; Suzuki, H.; Nagae, Y.; Kinoshita, T.; Chancharunee, S.; Fuji, K. Org. Lett. 2000, 2, 3883-3885.
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Org. Lett
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Kawabata, T.1
Chen, J.2
Suzuki, H.3
Nagae, Y.4
Kinoshita, T.5
Chancharunee, S.6
Fuji, K.7
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16
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0142245598
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(c) Kawabata, T.; Kawakami, S.; Majumdar, S. J. Am. Chem. Soc. 2003, 125, 13012-13013.
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J. Am. Chem. Soc
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, pp. 13012-13013
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Kawabata, T.1
Kawakami, S.2
Majumdar, S.3
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17
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0037429110
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(d) Kawabata, T.; Kawakami, S.; Shimada, S.; Fuji, K. Tetrahedron 2003, 59, 965-974.
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(2003)
Tetrahedron
, vol.59
, pp. 965-974
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Kawabata, T.1
Kawakami, S.2
Shimada, S.3
Fuji, K.4
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18
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18844438937
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(e) Kawabata, T.; Majumdar, S.; Tsubaki, K.; Monguchi, D. Org. Biomol. Chem. 2005, 3, 1609-1611.
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Org. Biomol. Chem
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Kawabata, T.1
Majumdar, S.2
Tsubaki, K.3
Monguchi, D.4
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19
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20344373648
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(f) Kawabata, T.; Chen, J.; Suzuki, H.; Fuji, K. Synthesis 2005, 5, 1368-1377.
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(2005)
Synthesis
, vol.5
, pp. 1368-1377
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Kawabata, T.1
Chen, J.2
Suzuki, H.3
Fuji, K.4
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20
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0010095120
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For reviews of stereoselective C-C bond formation based on enolate chemistry, see (a) Morrison, J. D. Ed, Academic Press, Inc, New York
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For reviews of stereoselective C-C bond formation based on enolate chemistry, see (a) Morrison, J. D. Ed. Asymmetric Synthesis; Academic Press, Inc.: New York, 1984; Vol.3, pp 1-341.
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(1984)
Asymmetric Synthesis
, vol.3
, pp. 1-341
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23
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41149095806
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(d) Fringuelli, F.; Piermatti, O.; Pizzo, F. Recent Res. Dev. Org. Chem. 1997, 1, 123-136.
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Recent Res. Dev. Org. Chem
, vol.1
, pp. 123-136
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Fringuelli, F.1
Piermatti, O.2
Pizzo, F.3
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25
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41149142181
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The racemization barrier at 20°C was roughly estimated from that at -78 °C based on the assumption that ΔS‡ of the unimolecular racemization process (bond rotation along the chiral C-N axis) is nearly zero.
-
The racemization barrier at 20°C was roughly estimated from that at -78 °C based on the assumption that ΔS‡ of the unimolecular racemization process (bond rotation along the chiral C-N axis) is nearly zero.
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27
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0141674056
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Mashchenko, N. V.; Matveeva, A. G.; Odinets, I. L.; Matrosov, E. I.; Petrov, E. S.; Terekhova, M. I.; Matveev, A. K.; Mastryukova, T. A.; Kabachnik, M. I. Zh. Obshch. Khim. 1988, 58, 1973-1979.
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(1988)
Zh. Obshch. Khim
, vol.58
, pp. 1973-1979
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Mashchenko, N.V.1
Matveeva, A.G.2
Odinets, I.L.3
Matrosov, E.I.4
Petrov, E.S.5
Terekhova, M.I.6
Matveev, A.K.7
Mastryukova, T.A.8
Kabachnik, M.I.9
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29
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24944499725
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(b) Carlier, P. R.; Lam, P. C.-H.; DeGuzman, J. C.; Zhao, H. Tetrahedron: Asymmetry 2005, 16, 2998-3002.
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(2005)
Tetrahedron: Asymmetry
, vol.16
, pp. 2998-3002
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Carlier, P.R.1
Lam, P.C.-H.2
DeGuzman, J.C.3
Zhao, H.4
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30
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0034712270
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For recent reviews on the importance and preparation of cyclic amino acids with a tetrasubstituted stereocenter, see (a) Cativiela, C, Díaz-de-Villegas, M. D. Tetrahedron: Asymmetry 2000, 11, 645-732
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For recent reviews on the importance and preparation of cyclic amino acids with a tetrasubstituted stereocenter, see (a) Cativiela, C.; Díaz-de-Villegas, M. D. Tetrahedron: Asymmetry 2000, 11, 645-732.
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33
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41149120896
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Commercial (not dry) DMSO was used without further purification
-
Commercial (not dry) DMSO was used without further purification.
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-
-
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34
-
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41149150588
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One might suppose that the active base in these reactions is a dimsyl anion generated in a small quantity from KOH and DMSO pKa's of H2O and DMSO in DMSO are 31 and 35, respectively; ref 7, However, this seems not feasible because the dimsyl anion prepared from KH in DMSO showed a different reactivity in the reaction of 1. Treatment of 1 with 3.0 mol equiv of potassium dimsylate in DMSO at 20°C for 2 h gave 2 in 99% ee and 68% yield together with the corresponding carboxylic acid of 2 in 25% yield
-
2O and DMSO in DMSO are 31 and 35, respectively; ref 7). However, this seems not feasible because the dimsyl anion prepared from KH in DMSO showed a different reactivity in the reaction of 1. Treatment of 1 with 3.0 mol equiv of potassium dimsylate in DMSO at 20°C for 2 h gave 2 in 99% ee and 68% yield together with the corresponding carboxylic acid of 2 in 25% yield.
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-
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35
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41149134172
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Whereas determination of the racemization barrier of the enolate generated from 28 with KOH/DMSO is desirable, it was not possible. This is because (1) KOH/DMSO cannot be used at low temperatures suitable for the measurement of enolate racemization, and (2) KOH/DMSO cannot generate the enolate from 28 in a quantitative manner. Quantitative generation of the enolate in a much shorter period than the half-life of racemization of the enolate is indispensable for the measurement of the racemization barrier.
-
Whereas determination of the racemization barrier of the enolate generated from 28 with KOH/DMSO is desirable, it was not possible. This is because (1) KOH/DMSO cannot be used at low temperatures suitable for the measurement of enolate racemization, and (2) KOH/DMSO cannot generate the enolate from 28 in a quantitative manner. Quantitative generation of the enolate in a much shorter period than the half-life of racemization of the enolate is indispensable for the measurement of the racemization barrier.
-
-
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36
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84987564680
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Amine-free lithium enolates have been known to be more reactive than the enolates in the presence of a secondary amine generated in situ by abstraction of the α proton of the carbonyl group with the lithium amide base; see (a) Laube, T, Dunitz, J. D, Seebach, D. Helv. Chim. Acta. 1985, 68, 1373-1393
-
Amine-free lithium enolates have been known to be more reactive than the enolates in the presence of a secondary amine generated in situ by abstraction of the α proton of the carbonyl group with the lithium amide base; see (a) Laube, T.; Dunitz, J. D.; Seebach, D. Helv. Chim. Acta. 1985, 68, 1373-1393.
-
-
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37
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33845551868
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(b) Seebach, D.; Boes, M.; Naef, R.; Schweizer, W. B. J. Am. Chem. Soc. 1983, 105, 5390-5398.
-
(1983)
J. Am. Chem. Soc
, vol.105
, pp. 5390-5398
-
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Seebach, D.1
Boes, M.2
Naef, R.3
Schweizer, W.B.4
-
39
-
-
41149160571
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-
We suppose that a water molecule generated by deprotonation of the substrate with KOH may be excluded from the coordination sphere of the potassium enolate by strongly coordinating DMSO molecules
-
We suppose that a water molecule generated by deprotonation of the substrate with KOH may be excluded from the coordination sphere of the potassium enolate by strongly coordinating DMSO molecules.
-
-
-
-
40
-
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41149162462
-
-
50/100 was roughly estimated to be 0.02 sec at 20°C based on the racemization barrier of C (15.5 kcal/mol).
-
50/100 was roughly estimated to be 0.02 sec at 20°C based on the racemization barrier of C (15.5 kcal/mol).
-
-
-
-
41
-
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41149112249
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-
For an additional example, seven-membered cyclization of a substrate derived from L-phenylalanine gave the product in 49% ee (25% yield) by treatment with powdered KOH in dry DMSO at 20°C for 2 h.
-
For an additional example, seven-membered cyclization of a substrate derived from L-phenylalanine gave the product in 49% ee (25% yield) by treatment with powdered KOH in dry DMSO at 20°C for 2 h.
-
-
-
-
42
-
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41149146870
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The rates of enolate formation from the substrates undergoing four-membered cyclization are assumed faster than those undergoing six-membered cyclization. Reasons are totally unclear. A possible explanation might be due to the slight increase in the acidity of α proton in the former substrates caused by the inductive effect of the bromo group at the N-2-bromoethyl substituent or due to the favorable delivery of OH- via chelation of K+ with the bromo group
-
+ with the bromo group.
-
-
-
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43
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33748727771
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For examples, see: a
-
For examples, see: (a) Pang, Y.-P.; Hong, F.; Quiram, P.; Jelacic, T.; Brimijoin, S. J. Chem. Soc., Perkin Trans 1 1997, 171-176.
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(1997)
J. Chem. Soc., Perkin Trans 1
, pp. 171-176
-
-
Pang, Y.-P.1
Hong, F.2
Quiram, P.3
Jelacic, T.4
Brimijoin, S.5
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47
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34247505849
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(e) Andreeva, O. V.; Militsina, O. I.; Kovylyaeva, G. I.; Korochkina, M. G.; Strobykina, I. Y.; Bakaleinik, G. A.; Al'fonsov, V. A.; Kataev, V. E.; Musin, R. Z. Russ. J. Gen. Chem. 2007, 77, 469-473.
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(2007)
Russ. J. Gen. Chem
, vol.77
, pp. 469-473
-
-
Andreeva, O.V.1
Militsina, O.I.2
Kovylyaeva, G.I.3
Korochkina, M.G.4
Strobykina, I.Y.5
Bakaleinik, G.A.6
Al'fonsov, V.A.7
Kataev, V.E.8
Musin, R.Z.9
-
48
-
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0027376442
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-
For an example, see
-
For an example, see, Dechoux, L.; Ebel, M.; Jung, L.; Stambach, J. F. Tetrahedron Lett. 1993, 34, 7405-7408.
-
(1993)
Tetrahedron Lett
, vol.34
, pp. 7405-7408
-
-
Dechoux, L.1
Ebel, M.2
Jung, L.3
Stambach, J.F.4
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